(1) Field of the Invention
The present invention relates to the field of prosthetic and orthotic liners and/or sleeves (i.e. skin-socket interface liners and sleeves), and more particularly to custom and production (“off the shelf”) prosthetic liners, sleeves, and associated methods.
(2) Discussion of Related Art
Liners provide a soft, flexible interface between a residual limb of an amputee and a hard socket to which a prosthetic device is secured. Such liners are typically made of an elastomer material such as silicone. Such liners may also be used in connection with orthotic devices. Suspension sleeves are a flexible tube used to secure the prosthetic device to the patients limb. The sleeve may be a sealing sleeve, or a suspension sleeve. Both types start on the prosthetic device and finish on the patients limb. Supportive sleeves can be used in an orthotic device to support a joint or limb of a patient.
Prosthetic suspension liners are described in prior patents, and may be fabricated of elastomer or rubber materials, and are used to cushion a post-operative stump or residual limb with respect to a prosthesis that is installed over the residual limb and coupled to the liner, e.g. by a conventional locking device.
Such liners should conform closely with the residual limb, accommodate all surface contours and sub-surface bone elements of the residual limb, and provide a comfortable cushion between the residual limb and the hard socket of the prosthesis that is to be fitted over the residual limb. Various silicone rubber or elastomer materials are used for suspension liners. Such elastomer materials having an appropriate hardness/softness, elongation, tensile, and other properties, such as bio-inertness (resulting in no skin reaction), have been successfully used for suspension liners.
Similar to liners, orthotic or prosthetic sleeves are provided for supporting and reinforcing muscles, joints, and extremities of patients, and also provide an airtight seal between a residual limb of an amputee and a prosthesis socket worn by the amputee. Moreover, such sleeves are not limited to use for amputees but may be applied to existing limbs to provide support in a manner associated with conventional orthotic devices. These sleeves may be similarly fabricated of elastomer materials. The sleeves may be cylindrical, curved or include other anatomically conforming shapes.
The elastomer forming the liner or sleeve frictionally engages and remains attached to the skin of a residual limb so that the limb is retained within the prosthetic socket in a comfortable, non-irritating manner. For example, liners may be used for any level of amputation both upper and lower limb.
As an example, prosthetic liners are used to cushion the amputee's residual limb from shock during ambulation, however the liner extends higher than the center of the knee to aid in suspension. Such liners are made in most cases with tubular molds or two part molds. To reduce or eliminate any bunching behind the knee during sitting or flexing of the knee, manufacturers have tried several methods of pre-flexing the liner to reduce or eliminate the accumulation of excess material, or bunching, behind the knee. A common conventional method is to produce a bent male and female mold, e.g. as shown in U.S. Pat. No. 5,888,216 to Haberman. The mold includes three or more parts, two or more sections for the female and one or more for the male. This increases the labor and material costs of both the mold and the liner. Three or more part molds are less stable and can increase the rejection rate of the molded liner.